Blood drainage system



FIG. 1 is a top plan view of a blood drainage system, showing my new design;

FIG. 2 is a side elevational view thereof, the opposite side elevational view being identical thereto;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof; and,

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a blood drainage system, as shown. 